1500 X 450 Supercal SV Duplex Stainless Steel Direct Cylinder for use in traditional open vented systems. Resistant to all forms of corrosion including crevice-corrosion, pitting-corrosion, uniform-corrosion and stress-corrosion cracking, the unit offers a long operational life and with the absence of an anode to inspect, maintain or replace, running costs are reduced. Built to the highest possible standards with a focus on being environmentally friendly, the cylinder is specially designed to heat water quickly and retain its temperature for long.